Processing apparatus having specially configured pressure applying members



United States Patent Inventor Patrick L. Flnelli Sudbury, MassachusettsAppl. No. 714,690

Filed March 20, 1968 Patented Nov. 3, I970 Assignee Polaroid CorporationCambridge, Massachusetts in corporation of Delaware PROCESSING APPARATUSHAVING SPECIALLY CONFIGUREI) PRESSURE APPLYING MEMBERS 8 Claims, 5Drawing Figs.

U.S.Cl

' 95/89 Int. Cl. G03d 3/00 95/13,

Field of Search Y 89/(lnquired) [56] References Cited .UNITED STATESPATENTS 2,845,850 8/1958 Bing et a1 95/13 2,854,904 10/1958 Bishop 95/13Primary ExaminerNorton Ansher Assistant Examiner-Richard L. MosesAnomeys- Brown and Mikulka, William D. Roberson and Leonard S. SelmanABSTRACT: A pair of rigid spreader members, for use in a self-developingcamera, having adjacent portions spaced apart and resiliently urgedtoward one another to form a pressuregene'rating gap through whichphotographic sheet materials are movable to effect the spreading of aprocessing fluid as a layer therebetween. The sheet contacting surfaceof each spreader member is provided with a convex curvature extendingthe length of the gap, the degree of curvature of one such surface beingsubstantially greater than that of the other such surface.

CROSS REFERENCE TO RELATED APPLICATIONS The processing apparatus of thepresent invention is related to the subject matter disclosed incopending-U.S. Pat. applications Ser. No. 655,831 filed July 25, l967;Ser. No. 655,832 filed July 25, 1967; Ser. No. 655,833 filed July 25,1967; Ser. No. 655,834 filed July 25, 1967; Ser. No. 655,835 filed July25, 1967 now US. Pat. No. 3,498,196; and Ser. No. 687,183 filed Dec. 1,1967, all assigned to the same assignee.

SUMMARY OF THE INVENTION The present invention is directed to a devicewhichmay be incorporated in a self-developing camera wherein'aphotographic transfer image is produced by moving a pair of film sheetsincluding an exposed negative photosensitive sheet and a superposedpositive receiving sheet, between apair of juxtaposed pressure-applyingmembers for distributing a processing liquid or developer between and incontact with the sheets which are later separated. The preferredembodiment of the invention as disclosed herein provides a narrow gapbetween a pair of spring-mounted sheet metal members through which thesheets are moved while the liquid introduced between the sheets isspread uniformly between and in contact with the entire facing surfacesof the sheets in a direction opposite the movement of the sheetsrelative to'the pressure-applying sheet metal members.

The spreader system which incorporates the present invention has manyadvanced features including its integral-precise construction resultingin important savings in cost of manufacture, its compactnessand-lightweight and its removability for cleaning or repair from thephotographic cameras designed for its use therewith. The preferredembodiment of the spreading apparatus more particularly includes a pairof sheet metal spreaders bent precisely to form a pair of small-radiusedge means having a precisely defined gaptherebetween through which thesheets are pulled thereby rupturing a processing liquid-containing podcarried by the sheets andspreading the liquid between thesheets. Thesheet metal spreader members are permanently joined to a pair of springswhich serve the dual function of supporting the spreader members inexactly aligned juxtaposed relation to one another and further to urgesaid spreader members toward each other with just enough force toprovide a uniform spread of processing liquid between the photographicsheets with as small a pull force as is feasible.

This invention is particularly related to the shape of the gapformingmembers and in particular their profile along the length of the gap. Theshape of the gap is constantly changing as the film material is movedtherethrough. In the initial stage the gap must be such that the filmleader may be easily guided between the spreader members so that itextends outside the camera body in position to be grasped manually.During rupturing of the pod and cleaning out of the processing liquidtherefrom as well as during the spreading of the processing liquidbetween the film sheets the gap configuration plays a critical role inproviding a uniform spread of the processing liquid.

In the preferred embodiment of the invention the profiles of thesheet-contacting surfaces as determined along the length of the gap havea convex curvature and the degree of curvature or convexity isdeliberately greater on the positive sheetcontacting surface than on thenegative sheet-contacting surface. This curvature provides a gapconfiguration which appears slightly "pinched" in the middle. Thespreader members forming the gap between them are supported at eitherend by spring members and those unsupported areas especially at thecenter experience a certain amount of deflection due to the forcesthereon. These forces include the damming force of the processing fluidas it is spread between the film sheets after rupture of the pod as wellas the forces due to spring load and friction on the spreading members.The convex curvature of the sheet-contacting surfaces prevent thedeflection of the surfaces from widening the gap more than apredetermined amount across the length of the gap. The curvature of thesheet-contacting surfaces, however, are actually greater than thatrequired for deflection compensation alone. For best results the surfacecontacting the positive sheet which is relatively thicker and stifferthan the negative sheet should have a slightly greater degree ofconvexity than does the sheet-contacting surface contacting the thinner,more flexible negative sheet.

The convex curvatures of the sheet-contacting surfaces improve thecompleteness of coverage of the actualpicture area of the film sheets bythe processing fluid. They also contribute to the uniformity of thethicknessof the processing fluid layer. For example, ifeithersheet-contacting surface were initially flat or concave, thedeflection of the surface during the spreading operation would result inan excess of processing fluid flowing to the widened part of the gap.This may cause a mottling in the final print or even failure of thefluid to completely cover the picture area since the amount ofprocessing fluid is limited. The convex curvatures of thesheetcontacting surfaces, especially atthe ends of the gap, also relieveand control certain damming forces acting on the fluid due to theeffective sealing of the longitudinal edges of the film sheet to preventfluid leakage as the film sheets are moved through the gap between thespreader members.

Accordingly, it is an object of this invention to provide photographicapparatus having an improved liquid-distributing device in position tospread a processing liquid in a uniform layer ofpredetermined thicknessbetween a pair of photographic sheets. I

It is another object of this invention to provide improvedliquid-distributing photographic apparatus including apair of juxtaposedpressure-applying nonrolling spreader members having a gap therebetweenthrough which a pair of photographic sheets are movable while processingliquid is spread therebetween, the pressure-applying members on eitherside of said gap each having convex curvatures extending substantiallythe entire length of said gap and cooperating with the respectivephotographic sheet contacted by each to provide improved spreadingperformance.

Other objects of the invention will in part be obvious and will in partappear hereinafter.

The invention accordingly comprises the apparatus possessing theconstruction, combination of elements and arrangement of parts which areexemplified in the following detailed disclosure, and the scope of theapplication of which will be indicated in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of acamera having mounted within and shown in cross section,'theliquid-distributing processing apparatus of the preferred embodiment ofthe invention including the spring-mounted sheet metal spreader membershaving a gap therebetween through which the photographic sheet may'bedrawn. 1

FIG. 2 is a perspective view of the processing apparatus shown removedfrom a camera.

FIG. 3 is an enlarged front view of the processing apparatus showing thegap between the spreader members and the configuration of thesheet-contacting surfaces of the spreader members along the length ofthe gap.

FIGS. 4 and 5 are fragmentary cross-sectional views along lines 4-4 ofFIG. 2 showing the respective sheet-contacting surfaces of the spreader.

DESCRIPTION OF THE PREFERRED EMBODIMENT The photographic apparatus ofthe present invention including the processing liquid spreader has manyadvantages including removability of the spreader from the camera foreasy cleaning, repair or replacement as well as economy of manufacture.This invention is directed, however, to the spreading function and inparticular with the configuration or profile of the sheet-contactingsurfaces as measured along the length of. the gap between spreadermembers as described in the following detailed description.

FIG. 1 shows the spreader apparatus 10 mounted in operable positioninside a photographic camera. The film sheets as shown in FIG. 1 are inprocessing position ready to be removed from the camera. U.S. Pat. No.2,991,702 shows a plurality of such film sheets stacked in a film packas they are 'used in many of the present day self-developing cameras. ln

picture-taking position, the negative sheet 12 with its photosensitivesurface faces the open front of the film pack and the taking lens andthen is pulled around and on top of the positive sheet 14 by tab 16 asshown in FIGS. 1 and 2 in superposed position ready for processing. Tab16 pulls the leader 18 through the gap between the sheet metal spreadermembers 20 and 22 which are supported and biased toward one another byspring members 24 and 26. The leader 18 is then manually grasped and thephotographic material including the negative I sheet 12 and the positivesheet 14 and the processing liquidcontaining pod 28 is pulled throughthe gap whereby the pod is broken and the processing liquid 30 isuniformly spread between the positive and negative sheets.

FIG. 2 is a detailed perspective view of the processing apparatusremoved from the camera illustrating features of the apparatus which arethe subject of the aforementioned applications, including the springseparating means 32, the spring restraining means 34, the platformrelief 36 and the edge control means 38.

FIG. 3 is a front view of the preferred embodiment of the spreadingapparatus showing in an exaggerated manner, for purposes of clarity, thecurvature of the sheet-contacting surfaces 40, 42 of the rigid spreadermembers 20 and 22. To initially provide a gap between the pair of rigidspreader members so that the film leader 18 may be manually pulledthrough the gap by means of tab 16, a pair of raised surfaces 44 and 46are provided on spreader member 20 at both ends of the gap. Thesheet-contacting surface 40 of spreader member 20, which contacts thestiffer positive sheet 14 as shown in FIG. 4, is shown as having agreater degree or radius of convex curvature than that of the curvedsheet-contacting surface 42 on member 22 which contacts the moreflexible negative sheet 12. This points up an important aspect of theinvention; the degree of convexity of each curved sheet-contactingsurface is significantly related to the flexibility of the sheet that itactually contacts. Thus, the surface contacting the stiffer positivesheet is made to have the specific contour to most effectively react inconjunction with that particular sheet to control and direct the flow ofprocessing liquid which is to be spread between the film sheets as thesheets are forceably drawn between the gap-forming members. It isimportant to note that even seemingly minute changes in the shape of thesheet-contacting surfaces can easily make the difference betweenacceptable and on nonacceptable spread control. Thus making provisionfor the flexibility for the particular sheet contacted by making theseslight changes in degree of convexity can and does remarkably effect theperformance of the spread system. In the preferred embodiment, as shownin FIG. 3, the end-toend contour of each sheet-contacting surfaceconstitutes a circular arc symmetrical about center line C.

FIG. 4 shows the film material including the processingliquid-containing pod 28 and the positive and negative sheets 14 and 12in position to be moved between the spreader members 20 and 22. FIG.shows the film after the pod 28 has been ruptured and the liquid 30 isbeing spread between the thicker, less flexible positive sheet 14 andthe thinner, more flexible negative sheet 12 by the positivesheet-contacting surface 40 and the negative sheet-contacting surface 42on the respective spreader members.

The convex curvature of surfaces 40 and 42 may constitute a circulararc, as previously described, but is not limited thereto and may alsocomprise other curves and may even change slightly in degree ofcurvature along the length of the An example of a specific embodiment ofthe invention as described above has a pair of sheet-contacting surfacesof 9.23 cm. in length with the center points of the positive andnegative sheet-contacting surfaces extending .0 l 75 mm. and .0125 mm.into the gap, respectively, (as measured from an imaginary flatsheet-contacting surface) and a spring load of 2.8 lbs. per side on thespreader members.

The preferred embodiment as described above is directed toward use withcertain film sheet materials having predetermined thicknesses andflexibility. Other film materials which may have positive and negativesheets differing in these pro perties may require greater or lesscurvature of the sheet-contacting surfaces forming the gap between thespreader members. However, in all cases it has been found that theconvex curvature of both of said surfaces is required to control theflow of the processing fluid.

Thus the improved configuration of the sheet-contacting surfaces providein a simple structure a means which greatly and to an unexpected extentimproves performance in all stages of the movement of the film sheetsthrough the gap and especially in the uniform spreading of theprocessing fluid between the positive and negative sheets.

Since certain changes may he made in the above device without departingfrom the scope of the invention herein involved, it is intended that allmatter contained in the above description or shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense.

lclaim:

l. Photographic apparatus for distributing a liquid in a layer betweentwo layers of photographic sheet material, said apparatus comprising:

a pair of substantially rigid'members having adjacent portionspredeterminedly spaced apart to form a narrow pressure-generating gapthrough which said sheet material is movable, a sheet-contacting surfaceon each of said rigid members located at said narrow gap and extendingcoextensively the length of said gap, said sheet-contacting surfaceseach having a convex curvature extending substantially the entire lengthof said gap, the degree of curvature of one of said sheet-contactingsurfaces being greater than the degree of curvature of the other of saidsheet-contacting surfaces; and

means for urging said members toward one another in a manner to effectthe spreading of said liquid in a layer between the sheets of saidphotographic material during movement of said material through said gap.

2. Photographic apparatus for distributing a processing liquid in alayer between two layers of photographic sheet material, said apparatuscomprising:

a pair substantially rigid nonrolling members having adjacent portionspredeterminedly spaced apart to form a narrow pressure-generating gapthrough which said sheet material is movable, and a pair of facingsurfaces on said members converging angularly toward each other todefine a narrow throat to guide said sheet material toward said narrowgap, a sheet-contacting surface on each of said rigid members located atsaid narrow gap and extending coextensively the length of said gap, saidsheetcontacting surfaces each having a convex curvature extendingsubstantially the entire length of said gap, the degree of curvature ofone of said sheet-contacting surfaces being greater than the degree ofcurvature of the other of said sheet-contacting surfaces; and

means for urging said members toward one another in a manner to effectthe spreading of said liquid in a layer between the sheetsof saidphotographic material during movement of said material through said gap.v

3. Photographic apparatus for distributing a liquid in a layer betweentwo layers of photographic sheet material, said apsaid rigid memberslocated at said narrow gap and extending coextensively the length ofsaid gap, said sheetcontacting surfaces each forming a convex circulararc extending substantially the entire length of said gap, the radius ofcurvature of one of said sheet-contacting surfaces being greater thanthe radius of curvature of the other of said sheet-contacting surfaces;and

means for urging said members toward one another in a manner to effectthe spreading of saidliquid in a layer between the sheets of saidphotographic material during movement of said material through said gap.

4. Photographic apparatus for distributing a processing liquid in alayer between two layers of photographic sheet material, one of saidlayers comprising a relatively flexible sheet and the other of saidlayers comprising a relatively stiff sheet, the liquid being dispensedina measured quantity and spread between the sheets, said apparatuscomprising:

a pair of substantially rigid members having adjacent portionspredeterminedly spaced apart to form a narrow pressure-generating gapthrough which said sheet material is movable, sheet-contacting surfaceson each of said rigid members located at said narrow gap and each ofsaid sheet-contracting surfaces having a convex curvature extendingsubstantially the entire length of said gap, the degree of convexity ofsaid sheet-contacting surface contacting said relatively stiff sheet ofphotographic material being greater than the degree of convexity of saidsheetcontacting surface contacting said relatively flexible sheet ofphotographic material; and

means for supporting and aligning said members in juxtaposed relation toone another so that said gap is formed between them and for urging saidmembers toward one another so that asvtlie photographic sheets are movedthrough said gap the processing fluid is spread in a uniform layerbetween said sheets.

5. Photographic apparatus for distributing a processing liquid in alayer between two layers of photographic sheet material, one of saidlayers comprising a thin relatively flexible negative sheet and theother of said layers comprising a less flexible positive sheet, theliquid being dispensed in a measured quantity and spread between thesheets, said apparatus comprising:

a pair of substantially rigid members having adjacent portionspredeterminedly spaced apart to form a narrow pressure-generating gapthrough which said sheet-material is movable, and a pair of facingsurfaces on said members converging angularly toward each other todefine a narrow throat to guide sheet material toward said narrow gap, apositive sheet-contacting surface on one of said rigid members locatedat said narrow gap and a negative sheet-contacting surface on the otherof said rigid members at said gap, said positive and negativesheet-contacting surfaces each having a convex curvature extendingsubstantially the entire length of said gap and the degree of curvatureof said positive sheet-contacting surface being greater than the degreeof curvature of said negative sheet-contacting surface; and

means for supporting and aligning said members in juxtaposed relation toone another so that said gap is formed between them and for urging saidmembers toward one another so that as the photographic sheets are movedthrough said gap the processing fluid is spread in a uniform layerbetween said sheets.

6. Photographic apparatus for distributing a processing liquid in alayer between two layers of photographic sheet material, one of saidlayers comprising a relatively flexible negative sheet and the other ofsaid layers comprising a relatively stiff positive sheet, the liquidbeing dispensed in a measured quantity and spread between the sheets,said apparatus comprising:

.a pair of substantially rigid members having adjacent portionspredeterminedly spaced apart to form a narrow pressure-generating gapthrough which said sheet material Is movable, and a pair of facingsurfaces on said members converging angularly toward each other todefine a narrow throat to guide sheet material toward said narrow gap, apositive sheet-contacting surface on one of said I rigid members locatedat said narrow gap and a negative sheet-contacting surface on the otherof said rigid members at said gap, said positive and negativesheet-contacting surfaces each forming a convex circular are extendingsubstantially the entire length of said gap, the radius of curvature ofsaid positive sheet-contacting surface being greater than the radius ofcurvature of said negative sheet-contacting surfaces;and

means for supporting and aligning said members in juxtaposed relation toone another so that said gap is formed between them and for urging saidmembers toward one another so that as'the photographic sheets are movedthrough said gap the processing fluid is spread in a uniform layerbetween said sheets.

7. Photographic apparatus for distributing a processing liquid in alayer between two layers of photographic sheet material, one of saidlayers comprising a thin relatively flexible negative sheet and theother of said layers comprising a less flexible positive sheet, aprocessing liquid-containing pod carried by one of said sheets inadvance of said positive sheet and adapted to be ruptured by saidapparatus and the liquid spread between the sheets, said apparatuscomprising:

a pair of substantially rigid nonrolling members having adjacentportions predeterminedly spaced apart to form a narrowpressure-generating gap through which said sheet material is movable,and a pair of facing surfaces on said members converging angularlytoward each other to define a narrow throat to guide sheet materialtoward said narrow gap, a positive sheet-contacting surface on one ofsaid rigid members located at said narrow gap and a negativesheet-contacting surface on the other of said rigid members at said gap,said positive and'negative sheetcontacting surfaces each having a convexcurvature extending substantially the entire length of said gap and thedegree of curvature of said positive sheet-contacting surface beinggreater than the degree of curvature of said negative sheet-contactingsurface; and

a pair of spring means fastened to at least one of said rigid members atrespectively opposite ends of said narrow gap for supporting andaligning said members in juxtaposed relation to one another so that saidgap is formed between them and for urging said members toward oneanother so that as the photographic sheets are moved through said gapthe processing fluid is spread in a uniform layer between said sheets.

8. Photographic apparatus for distributing a processing fluid in a layerbetween two layers of sheet material, said apparatus comprising:

a pair of substantially rigid members having adjacent portionspredeterminedly spaced apart to form a narrow pressure-generating gapthrough which said sheet material is movable, a sheet-contacting surfaceon each of said rigid members located at said narrow gap and extendingcoextensively the length of said gap, each of said sheetcontactingsurfaces having a convex curvature extending substantially the entirelength of said gap, the degree of curvature of one of saidsheet-contacting surfaces being greater than the degree of curvature ofthe other of said sheet-contacting surfaces; and

means for urging said members toward one another in a manner to effectthe spreading of said liquid in a layer between said layers of sheetmaterial during movement of said material through said gap.

